RMQSI Answers ForumCategory: Handbooks and StandardsFailure rate calculations based on FMD
mamarzec asked 7 years ago

Hello,
Currently I’m working on FMECA analysis of HVAC system. System includes temperature controller (in FMD: controller, temperature). FMD-2013 indicates that failure mode distributions for that component are:
[CRACKED] 0,387
[INOPERATIVE]” 0,29
[BROKEN] 0,129
[DAMAGED] 0,097
[MALFUNCTIONED] 0,097
[OTHER] 0,097

In our analysis we assumed that each component is used and maintained correctly. According to that failure mechanism like: [CRACKED]; [BROKEN] (mechanical failures) are not applicable.

Supplier has assumed us that Failure Rate (empirical) of that part is: 14 FPMH.

So, according to our assumptions, FMD and supplier data we calculated that Failure Rate in our case will be:

1-0,387[CRACKED]-0,129 [BROKEN]=0,484
Failure rate in our case is: 0,484*14 FPMH=6,8 FPMH

Based on information contained in FMD introduction I know that if some Failure Mode is not applicable we should recalculate % (sum of distributions must equal 1) but our case is different (according to assumptions).

Am I right?

Regards